1. Related Technical Fields
Related technical fields include image display devices, image display methods, and programs that enable a user to perform a scroll operation of an image through pressing a screen.
2. Related Art
Conventionally, devices provided with a liquid crystal display such as in-vehicle navigation devices, portable information equipments including PDAs (Personal Digital Assistants) and cellular phones, portable music players, portable game devices, personal computers, and the like are likely to have a touch panel or the like on the front face of the liquid crystal display to accept a user's operation. On the devices provided with a touch panel, it is possible to perform a scroll operation of the image by moving a finger with the screen being pressed by the finger (i.e., perform a drag operation).
The touch panel here employs a system such as a resistive system (a pressure sensitive system), an electrostatic capacitance system, or the like. Pressed coordinate positions on the screen and a cancellation of pressing are detected based on a change in pressure or electrostatic capacitance generated when a part of the user's body (for example, a finger) or a pen has touched the touch panel. When performing the above-mentioned scroll operation, the finger of the user or the like may temporarily lift up from the touch panel or the pressure the touch panel is being pressed may be reduced while dragging against the user's intention. If a cancellation of the pressing on the screen (a touch-off) is determined in such case, the scroll may be temporarily stopped against the user's intention.
In order to solve the above-mentioned problem, the following method is considered. A touch-off is not determined immediately after the touch-off was detected. That is, after the touch-off was detected, if a new pressing on the screen is detected within a predetermined time period, the touch-off is not determined under the assumption that the pressing on the screen continues. Only if a new pressing on the screen is not detected within the predetermined time period, the touch-off is determined. For example, Japanese Patent Application; Publication No. 2002-366286 discloses a technology that, in a key input processing device including a unit that detects ON/OFF of a key at a predetermined interval, an OFF of a key input is determined when two or more OFFs have been sequentially detected.